The overall link between sleep apnea and cancer is less well-defined than the link between sleep apnea and heart disease or diabetes. However, there are some indications that sleep apnea could increase the risk of cancer, including the risk of breast cancer.
A Taiwanese Study
Perhaps the strongest link between sleep apnea and breast cancer comes from a recent study in Taiwan that looked at breast cancer rates for sleep apnea patients and compared them to a group of age-matched controls. There were 846 women diagnosed with sleep apnea compared to 4230 age-matched controls. All women were followed for five years and their breast cancer rates compared.
Among the sleep apnea group 12 women developed cancer, compared to 32 in the control group. Researchers calculated that this was the equivalent of a twofold increase in breast cancer risk because of sleep apnea. They also found that women who were 30 and older were more likely to develop breast cancer due to sleep apnea, but these conclusions weren’t statistically significant.
Researchers proposed that intermittent hypoxia (low oxygen) could be the mechanism by which sleep apnea stimulates the growth of cancers. However, they did not determine whether the degree of hypoxia or the severity of sleep apnea contributed to cancer risk. Based on their results for the aged-based risk, it’s likely that this study is just too small to answer such questions.
Women Should Be Screened for Sleep Apnea
Although snoring and sleep apnea are commonly associated with men, many women have sleep apnea and go undiagnosed. Sleep apnea increases many health risks for women, in addition to breast cancer. If you have symptoms of sleep apnea, such as:
- Daytime sleepiness
- Lack of interest
You should talk to your doctor about sleep apnea, especially if you are postmenopausal.